code: def test_gradcheck(self, num_points, device, dtype):
      intrinsics, _, world_points, img_points = self._get_test_data(
          num_points, device, dtype
      )
  
      world_points = tensor_to_gradcheck_var(world_points)
      img_points = tensor_to_gradcheck_var(img_points)
      intrinsics = tensor_to_gradcheck_var(intrinsics)
  
      assert gradcheck(
          kornia.geometry.solve_pnp_dlt,
          (world_points, img_points, intrinsics),
          raise_exception=True,
          fast_mode=True,
      )
  
file_path: kornia/test/geometry/calibration/test_pnp.py
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia
  from kornia.geometry.calibration.pnp import _mean_isotropic_scale_normalize
  from kornia.testing import assert_close, tensor_to_gradcheck_var
label_desc: Use image node_id 6 for calling the TestSolvePnpDlt obj's underlying member method code with example usage: obj.test_gradcheck(num_points, device, dtype) without return types